Grinding machine



Nov. 25, 1952 o. E. HILL GRINDING MACHINE Filed Jan. 10, 1950 INVENTQR 0/ m E. HILL gym UAW Nov. 25, 1952 o. E. HILL 2,618,909

GRINDING MACHINE Filed Jan. 10, 1950 6 Sheets-Sheet 3 01w; 5 H/1 L 1511;. 5 BYMQ.W

' Nov. 25, 1952 o. E. HILL 2,613,909

GRINDING MACHINE Filed Jan. 10, 1950 6 Sheets-Sheet 5 INVENTOR 01w; 5 HILL 14 7"TO Y E Y Nov. 25, 1952 o. E. |-m 2,618,909

GRINDING MACHINE Filed Jan. 10, 1950 s Sheets-Sheet 6 Ame/wry Patented Nov. 25, 1952 mists GRINDING MACHINE Oiva E. Hill, West Boylston, Mass, assignor to Norton Company, Worcester, Mass, at corporation of Massachusetts Application January 10, 1950, Serial No. 137,834

13 Claims.

The invention relates to grinding machines, and more particularly to a grinding machine for simultaneously grinding the opposed edges of a workpiece.

One object of the invention is to provide a simple and. thoroughly practical grinding machine for grinding the opposed spaced edges of a workpiece. Another object is to provide a grinding machine with a pair of opposed spaced grinding wheels which are arranged simultaneously to grind partial cylindrical surfaces on, opposed spaced edges of a workpiece, such as, a turbine or jet motor blade. Another object of the invention is to provide a turret-type work holder to convey workpieces to and from a grinding position. Another object of the invention is to provide a turret-type work holder for conveying workpieces to and from a grinding position which serves also to support the workpiece during a grinding operation. Another object of the invention is to provide a work driving mechanism for rotating the workpiece relative to the turret when it is in an operative grinding position to grind partial cylindrical faces on opposite edges of a workpiece.

A further object is to provide a hydraulically operated turret locating and work driving head which is arranged to locate the work turret precisely in a predetermined indexed position, and to oscillate the workpiece to be ground between the opposed spaced operative faces of a pair of spaced rotatable grinding wheels. Another object is to provide a transversely movable hydraulically operated slide for supporting the work turret and the turret locating work driving head. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which is shown one possible embodiment of the mechanical features of this invention:

Fig. 1 is a plan view of the improved grinding machine;

Fig. 2 is a rear elevation of the grinding machine;

Fig. 3 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 1, showing the work turret and associated parts;

.Fig. 4 is a fragmentary horizontal sectional view, on an enlarged scale, taken approximately on the line l-A of Fig. 3, through one of the work holders and associated parts;

Fig. 5 is a fragmentary horizontal sectional view, on an enlarged scale, of the work supporting and driving mechanism;

Fig. 6 is an elementary side elevation, on an enlarged scale, of the work turret and driving mechanism therefor;

Fig. 7 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 'i-l of Fig. 1, through the wheel slide feeding and adjusting mechanism;

Fig. 8 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 8--8 of Fig. 1, through the wheel slide base feeding and adjusting mechanism;

Fig. 9 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 9-9 of Fig. 1, through the wheel slide nut and screw feeding mechanism;

Fig. 10 is a combined hydraulic and electrical diagram;

Fig. 11 is a fragmentary vertical sectional view, taken approximately on the line HH of Fig. 4, showing the mechanism for actuating the work driving spindle;

Fig. 12 is a diagrammatic showing of the Workpiece and its movement relative to the grinding wheels; and

Figure 13 is a fragmentary plan view, on an enlarged scale, showing the opposed grinding wheels and the workpiece with fragments of the work supports shown in section.

As illustrated in the drawings the grinding machine embodying this invention comprises a base I!) having a transversely movable wheel slide base II which is arranged to slide transversely on a fiatway l2 and a V-way I3. The wheel slide base H serves as a support for a wheel slide it which is arranged to slide on a flatway l5 and a V-way l6 formed on the upper surface of the wheel slide base H. The wheel slide i4 is provided with a rotatable wheel spindle I! which is journalled in bearings (not shown) and serves as a support for a grinding wheel It. Any suitable driving mechanism may be provided for rotating the wheel spindle I? and the grinding -wheel 18 such as for example an electric motor i9 mounted on the upper surface of the wheel slide Hi. The motor I9 is provided with a multiple V-groove pulley 2a which is connected by multiple V-belts 2| with a multiple V-groove pulley 22 mounted on the end of the wheel spindle ii.

The base It also supports a second wheel slide 3 base 3| on a flatway 32 and a V-way 33 for a transverse adjustment relative thereto. The wheel slide base 3| serves as a support for a wheel slide 34. A flatway 35 and a V-way 36 are provided between the wheel slide base 3| and the wheel slide 34 to facilitate a transverse adjustment of the wheel slide 34 relative to the base I of the machine. The wheel slide 34 is provided with a rotatable wheel spindle 37 which is journalled in bearings (not shown) and serves as a support for a grinding wheel 38. A similar driving mechanism is provided for the spindle 31 and the grinding wheel 38 comprising an electric motor 39 mounted on the wheel slide 34.

The motor 39 is provided with a multiple V-groove pulley 43 which is connected by multiple V-belts 4| with a multiple V-groove pulley 42 mounted on the end of the wheel spindle 31.

A feeding mechanism is provided for adjusting the wheel slide base 3| transversely relative to the base It] comprising a rotatable feed screw 45 (Fig. 8) which is journalled in bearings 46 and 41 mounted in the base II] of the machine. The wheel slide base 3| is provided with a depending half nut 48 which meshes with or engages the feed screw 45. A gear 49 is mounted on the left hand end of the feed screw 45. The gear 49 meshes with a gear 50 rotatably supported on a shaft 5!. A manually operable feed wheel 52 is provided for manually imparting a rotary motion to the feed screw 45 to facilitate adjusting the wheel slide base 3| and the grinding wheel slide 34 as desired.

A similar feeding mechanism is provided between the wheel slide base 3| and the grinding wheel slide 34 comprising a feed screw 55 which is journalled in bearings 56 and 51 mounted in the wheel slide base SL The wheel slide 34 is provided with a depending half nut 58 which meshes with or engages the feed screw 55. A bevel gear 59 is mounted on the left hand end of the feed screw 55 which meshes with a bevel gear 60 (Fig. 9) mounted on the end of a rotatable shaft'BI. The shaft BI is journalled in bearings 62 and 63 (Fig. 7). A manually operable feed wheel 64 is mounted on the left hand end of the shaft 6| to facilitate a manual rotation of the feed screw 55 to facilitate adjusting the wheel slide 34 relative to the wheel slide base 3I A similar nut and screw feeding mechanism is interposed between the wheel slide base II and the base I!) which is actuated by a manually operable feed wheel 61. This mechanism is identical with that shown in detail in Fig. 8 and described above, consequently it has not been illustrated or described in detail. A similar nut and screw feeding mechanism is interposed between the wheel slide base I I and the wheel slide I4 to facilitate adjustment of the wheel slide I4 relative to the wheel slide base I I. This mechanism is actuated by means of a manually operable feed wheel 68. This feeding mechanism is identical with that illustrated in Figs. 7 and 9 and described above, consequently it has not been shown and described in detail.

As shown in Fig. 1 the grinding wheel spindles I1 and 3'! are angularly arranged to facilitate a shoulder grinding operation on a workpiece. The peripheries of the grinding'wheels I8 and 38 are frusto-conical in shape and present opposed operative faces for grinding opposed parallel faces on opposite sides of a workpiece. The upper faces of the wheels I8 and 38, as shown in Fig. l are beveled at right angles to the main face of the wheels so that the workpiece may be trav- 4 ersed relative thereto to grind a shoulder thereon.

A turret-type work holder is provided comprising a work turret Iii which is rotatably mounted on a shaft 'II in vertically arranged bearing brackets 72 and I3. The bearing brackets I2 and I3 are fixedly mounted on a transversely movable slide 74' (Fig. 2). The slide I4 is provided with a dovetailed slideway which mates with a correspondingly shaped slideway formed on the base I3. The shaft II is fixedly mounted relative to the brackets I2 and I3.

The work turret I0 is provided with a plurality of work holding devices arranged for successively conveying workpieces to the grinding wheels before a grinding operation has been completed.

As illustrated in Fig. 3, the turret wheel I3 is provided with a plurality of radially arranged work rotating holders 80, SI, 82 and 33 which are arranged to support workpieces 84, 85, 83 and 81 for successive grinding operations. All of the work holding devices are identical in construction, consequently only one of these devices has been illustrated in detail in Fig. 4. The work holding device 86 comprises a rotatable spindle 33 journalled in bearings 89 mounted within the turret wheel Ill. The other end of the device 83 is provided with a spindle 9%] which is journalled in bearings 9| which are mounted within the turret 1! A work supporting arbor 92 extends between the spindle and the spindle 88 and is fixedly mounted thereon. A spring pressed plunger 93 is contained within the spindle 38. A second slidably mounted plunger 94 is also contained within the spindle 83 and is arranged to ride upon a stationary cam 95 which is fixedly mounted on the shaft II. A small diameter relatively light compression spring 95 is interposed between the spring pressed plunger 33 and the plunger 94. Similarly a relatively heavy compression spring 91 surrounds the spring 96 and is interposed between the spring pressed plunger 93 and the plunger 94. The relatively light compression spring 95 serves to facilitate a loading operation whereas the relatively heavy compression spring 9! is actuated by the plunger 94 to look a workpiece on the arbor 92 during a grinding operation.

The left hand end of the spring pressed plunger 93 is provided with a beveled face 98. When it is desired to insert a workpiece into operative position on the arbor 32, the right hand end workpiece 34 is moved into engagement with the beveled face 38 of the spring pressed plunger 93 and the plunger 93 is moved toward the right until the head 99 of the workpiece may be dropped into a mating aperture I00 formed adjacent to the left hand end of the arbor 32.

As shown in Fig. 3, the high point of the cam 35 is arranged to move the plunger 94 outwardly to compress the spring 91 and thereby to lock the workpiece 84 in operative position on the arbor 92 during a grinding operation.

In order to grind a predetermined partial cylindrical surface on the opposed edges of the workpiece 84 when the turret I0 moves the arbor 32 and the spindles 88 and 33 into an operative grinding position, a spindle driving mechanism is provided. As illustrated in Fig. 4, a slidably mounted sleeve H0 is keyed within a cylindrical aperture I I I formed within a portion of the turret I3. A compression spring II2 serves normally to exert a pressure on the sleeve I I ll tending to move it toward an extreme left hand end position in which position an internal gear H3 formed within the sleeve I I0 meshes with an external gear 4 formed on the left hand end of the spindle 90. The gears I I3 and I I4 serve normally to hold the arbor 92 so that the workpiece 84 lies in a position at substantially right angles to its grinding position. A suitable mechanism is provided for unlocking the spindle 90 and rotating it through an arc of approximately 90 to generate a partial cylindrical surface on opposed spaced edges of the workpiece 84.

The work rotating mechanism may comprise a rotatable spindle II5 which is journalled in bearings H6 and H1 mounted within a transversely movable slide I I8. The slide H8 is preferably arranged so that the axis of the spindle H5 is axially aligned with the spindle 98 when the turret wheel is indexed into successive operative positions. A slidably mounted plunger I is contained within the spindle II5. A compression spring I2I serves normally to urge the plunger I20 toward the right (Fig. 4). The plunger I20 is provided with a frusto-conical end I22 which is arranged to engage a correspondingly shaped internal frusto-conical surface I23 formed within the right hand end of the spindle 90. When the slide H8 is moved toward the right from the position indicated in Fig. 4 to the position indicated in Fig. 5, the conical surface I22 engages the internal frusto-conical surface I23 and serves to precisely align the turret wheel 10 to position the work holding arbor 92 and its supporting spindles 88 and 90 in a predetermined grinding position. As the slide H8 is moved toward the right (Figs. 4 and 5), a collar I24 carried by the spindle I I5 engages the left hand end face of the sleeve H0 and moves it toward the right against the compression of the spring II2. This movement of the sleeve I I0 slides the internal gear H3 toward the right out of mesh with the external gear I I4 and at the same time moves an internal gear I25 formed within the collar I24 into mesh with the external gear H4 on the spindle 90. In this position of the parts, it will be readily apparent that a rotary motion of the spindle II5 will be transmitted through the mechanism above described to impart a rotary motion to the spindles 90 and 88.

A fluid pressure mechanism is provided for moving the slide H8 to and from an operative position. This mechanism as shown in Fig. 3 may comprise a cylinder I which is fixedly mounted on the slide I I8. The cylinder I30 contains a piston I3I which is connected to one end of a piston rod I 32. The other end of the piston rod I32 is connected to a bracket I33 formed integral with the transversely movable slide 14. When fluid under pressure is passed through a pipe I35 into the cylinder I30, the cylinder I30 and the slide II8 move downwardly (Fig. 10) or move toward the right (Fig. 4) to move the work driving spindle H5 and its associated parts into an operative position to impart a rotary motion to the spindle 90. A pipe I34 is connected to the other end of the cylinder I38. To facilitate controlling the movement of the slide II 8 into an operative position, a throttle valve [36 is provided in the pipe line I34. A ball check valve I31 is provided for bypassing fluid around the throttle valve I36 when the slide IE8 is moved toward an inoperative position.

A suitable fluid pressure mechanism is provided for imparting a rotary motion to the spindle 90. This mechanism may comprise a cylinder I48 mounted on the slide I I8. A piston MI is provided within the cylinder I40 and is connected to one end of a piston rod I42. The other end of the piston rod I42 is fixedly connected to an arm I43, the other end of which is fastened to the left hand end of a slidably mounted rack bar I 44 (Fig. 11). The rack bar I44 meshes with a gear I45 which is keyed on the left hand end of the spindle II5 (Figs. 4 and 5). When fluid under pressure is passed through a pipe I 48 into the cylinder I40, the piston I4I together with the rack bar I44 are moved toward the right into the position illustrated in Figs. 10 and 11. Similarly when fluid under pressure is passed through a pipe I49 into the cylinder I40, the piston IM together with the rack bar I44 are moved toward the left (Figs. 10 and 11) to impart a rotary motion to the driving spindle I I5 and the work spindle 90 so as to impart a rotary motion to the work supporting arbor 92 and the workpiece 84. In order to control the rate of movement of the piston MI and thereby to control the rotary motion of the spindles, a throttle valve I50 is provided to regulate fluid flowing through the pipe I 48. A ball check valve I 41 is provided to permit fluid to bypass the throttle valve I 50 to allow the piston IM to move at a rapid rate during its movement toward the right (Figs. 10 and 11) The hydraulic mechanism just described serves to rotate the workpiece for a grinding operation. The workpiece such as a jet blade 84 is positioned on the work supporting arbor 92 when the arbor is in a vertical position. In this position the blade is positioned as shown in dotted lines 84a (Fig. 12) with its cross sectional axis lying in a plane normal to the axis of the work turret 10. The movement of the piston I4I serves to rock the blade 84 from position 8411 into position 84b to grind a partial cylindrical surface I5I and I52 on opposed spaced edges of the blade 84. The edge portion of the blade 84 to be ground is longer than the width of the operative faces of the grinding wheels I8 and 38, consequently it is desirable to provide a suitable traversing mechanism for causing a relative longitudinal movement between the blade 84 and the grinding wheels I8 and 38 while the blade is in the horizontal position as illustrated in Fig. 12.

A fluid pressure mechanism is provided for traversing the transversely arranged slide 14 to cause a relative longitudinal movement between the blade 84 and the grinding wheels I8 and 38. This mechanism may comprise a cylinder I55 (Fig. 10) which contains a slidably mounted piston I56. The piston I56 is connected to one end of a piston rod I51. The right hand end portion of the piston rod IE1 is provided with a screw threaded portion I58. The threaded portion I58 of the piston rod I51 passes through a clearance hole in a bracket I59 depending from or fixedly mounted on the underside of the slide 14. A pair of nuts I60 and NH serve to lock the bracket I59 and the slide 14 on the threaded portion I58 of the piston rod I51. It will be readily apparent from the foregoing disclosure that by manipulation of the nuts I60 and "SI, the position of the bracket I59 and the slide 14 may be varied relative to the piston I56 to facilitate setting up th grinding machine.

In order to provide an adjustment for the stroke of the slide 14, the threaded portion I58 of the piston rod I51 passes through a clearance hole I62 formed in a lug I83 which is fixedly mounted relative to the base I0. Pairs of spaced nuts I64 and IE5, each having lock nuts associated therewith, are provided to serve as tops to limit the stroke of the piston I56 and the slide I51.

Fluid under pressure may be admitted through a pipe I66, through a ball check valve I61 and a pipe I68 into theleft hand end of the cylinder I55 to move the piston I 56 and the slide 14 toward the right. During the movement of the piston I56 toward the right, fluid within the right hand end chamber of the cylinder I55 exhausts through a pipe I69. During the movement of the piston I56 toward the right, an idle stroke is imparted to the slide 14. When fluid under pressure is admitted through the pipe I69 into the right hand end chamber of the cylinder I55 to cause an operative stroke of the piston I59 and the slide 14 toward the, left, fluid exhausting through the pipe I58 passes through a throttle valve I16 and thus bypasses the ball check valve I61. By adjusting the throttle valve I16, the rate of movement of the slide 16 may be readily controlled as desired.

Aball check valve I1I is provided in the pipe line I69 to allow free exhaust of fluid through the pipe I69 from the right hand end of the cylinder I55 during the return stroke of the slide 16.

It is desirable to provide a delayed action of the movement of the slide 14 to allow the slide I I6 to move into an operative position to connect the driving spindle H with the work spindle 96 and to allow the piston I lI to move toward the left (Fig. 10) so as to rotate the spindle 99 to move the workpiece from position 84a through approximately 90 into position 961) (Fig. 12) so as to grind the partial cylindrical faces I5I and I52 on the workpiece 64 before fluid is passed through the pipe I69 into the right hand end of the cylinder I55 to start the traversing movement of the slide 14. This is preferably accomplished by means of a fluid pressure actuated sequence valve I12 (Fig. 10) which is arranged so that when fluid is passed into the pipe I69, it first passes through a pipe I13 to move the piston of the sequence valve I12 toward the right against the compression of the spring within the right hand end of the valve I12. After the valve piston has moved toward the right, fluid under pressure in the pipe I69 may then pass through a valve chamber I14, thus bypassing the ball check valve Ill and into the right hand end of the cylinder I55 to start the traversing movement of the slide 19. This traversing movement of the slide 19 continues until the nut I65 engages the lug I69 thus limiting the movement of the work relative to the grinding wheels I8 and 33 so as to grind a predetermined shoulder portion on opposite sides of the blade 84. Due to the fact that less fluid under pressure is required to move the pistons I3I and MI, than is required moving the sequence valve I12, these pistons move and complete their operative strokes before the valve piston moves a suificient distance to uncover the valve chamber I14 thus delaying the admission of fluid under pressure, to other right hand end of the cylinder I55.

A suitable indexing mechanism is provided for indexing the work turret 19 to convey workpieces to and from a grinding position. This mechanism is preferably hydraulically operated and comprises a fluid motor I15 which is supported by a bracket or frame I16 which is in turn fixedly mounted on the transversely movable slide 14. The fluid motor I15 is preferably a constant displacement piston type fluid motor, such as that manufactured by Vickers Inc., of Detroit, Michigan and such as is shown in the prior United States Patent No. 2,464,309 to J. A. Martin dated July 16, 1946. The motor I15 serves to drive' a worm I11 (Fig. 6) which meshes with a worm gear I18 mounted on a shaft I19. The shaft I19 is journalle-d in a bracket I86 fixedly mounted on the transverse slide 14. A gear IBI is fixedly mounted on the shaft I19 and meshes with a gear I82 which is fixedly mounted on the work turret 16. When fluid under pressure is passed through a pipe I65 (Fig. 10) to the fluid motor I15. the turret wheel 16 will be rotated in a clockwise direction (Fig. 3) or in a counter clockwise direction (Fig. 6). During this movement, fluid is exhausted from the motor through a pipe I86.

In order to control the indexing movement of the work turret 16, a notched index plate I 96 (Figs. 6 and 10) is provided on the shaft I19. The index plate I96 is provided with a plurality of notches I9I, I92, I93 and I94. A vertically movable index pawl is normally held in engagement with the periphery of the index plate I96 by means of a compression spring I96. In order to withdraw the index pawl automatically to facilitate an indexing movement of the turret 16, a hydraulically operated mechanism is provided comprising a cylinder I91 having a slidably mounted piston I98 therein. When fluid under pressure is passed through a pipe I99, the piston I98 is moved downwardly to withdraw the pawl I from engagement with the notch in the index plate I96. The withdrawal of the index pawl I95 is controlled automatically in a manner to be hereinafter described.

When the pawl I95 is moved downwardly to an inoperative position, it engages the actuating plunger of a normally open limit switch LS2. During the movement of the pawl I95 to an operative position, a detent 26I which is fixedly mounted on the pawl plunger I95 engages and rocks a rock arm 262. The rock arm 262 is pivotally supported on a stud 263. The detent 26I during its upward movement under influence of the compression spring I96 rocks the rock arm 262 in a counterclockwise direction to momentarily depress an actuating plunger 294 of a normally open limit switch LS3.

To facilitate automatic operation of the machine, a cam plate 2I6 is fixedly mounted on the shaft I19. The plate 2I0 is provided with a plurality of cams 2II, 212, 2I3 and 2M which are fixedly mounted in the periphery thereof. As the plate 2I6 rotates during an indexing movement of the work turret 10, the cams 2II, 2I2, 2 I3 and 2M engage the actuating roller of a normally closed limit switch LSI and open the switch for purposes to be hereinafter described.

To facilitate removal of a workpiece from the supporting arbor, a work ejecting plunger 2I8 is provided. The plunger 2I6 is supported by a bracket 2| 9 which is fixedly mounted on the slide 14. The axis of the plunger 2I8 is positioned so that it is in axial alignment with the axis of the work spindle 96 when the work turret has been indexed through A compression spring 226 (Fig. 3) serves normally to hold the plunger 2I8 in an inoperative or left hand end position. When it is desired to remove a workpiece from the supporting arbor, the plunger I I8 is moved toward the right (Fig. 3). Movement of the plunger 2I8 toward the right engages and moves a slide rod 222 which is slidably keyed within a central aperture within the spindle 96 toward the right. Movement of the rod 222 toward the right (Fig. 5) serves to move the workpiece 84 toward the right against the compression of the spring 96. This movement of the workpiece 64 toward the right continues for'a sufficient distance so that the head 99 of the workpiece 84 moves sufliciently toward the right so that it is out of the aperture I09. In this position the workpiece 84 may be readily swung upwardly and thereby removed from supporting engagement on the work supporting arbor 92. This unloading operation takes place when the workpiece is indexed through 180 from the grinding position.

A hydraulically operated control system is provided for controlling the cycle of operation of the various mechanisms above described so that except for manual loading of the workpiece into position on the work turret 19, the machine functions automatically after it is initially started. A fluid pressure actuated control valve 225 is provided for controlling the admission of fluid under pressure to the fluid motor I15. The shifting movement of the control valve 225 is controlled by a pilot valve 225 which is in turn actuated in a manner to be hereinafter described by a solenoid S2. The control valve 225 comprises a slidably mounted valve member 221 which is shifted endwise by means of fluid under pressure from the pilot valve 226. A similar fluid pressure actuated control valve 228 is provided for regulating the exhaust of fluid from the fluid motor I15 to facilitate controlling the rate of movement of the motor during an indexing movement. The control valve 228 is actuated by a pilot valve 229 which is in turn actuated by means of a solenoid S4. The control valve 228 includes a slidably mounted valve member 239 which is shifted longitudinally by means of fluid under pressure as governed by the pilot valve 229. A fluid pressure actuated control valve 23I is provided for controlling the admission of fluid through the pipe I99 to the pawl actuating cylinder I91. The valve 23I is controlled by a pilot valve 232 which is in turn actuated by a solenoid SI. The control valve 23I includes a slidably mounted valve member 233 which is moved endwise by means of fluid under pressure as controlled by the pilot valve 232. A fluid pressure actuated control valve 234 is provided for controlling the admission of fluid to and the exhaust of fluid from the cylinders I39, I49 and I 5. The control valve 234 is controlled by a pilot valve 235 which is in turn actuated by a solenoid S3. The valve 234 includes a slidably mounted valve piston 236 which is shifted longitudinally by means of fluid under pressure as governed by the pilot valve 235.

A fluid pressure system is provided for supplying fluid under pressure to the various mechanisms of the machine. -This system may comprise a reservoir 240 which is preferably formed within the base ID of the machine. Fluid is pumped from the reservoir 240 through a pipe 24I by means of a motor driven fluid pump 242 and is forced under pressure through a pipe 243 to the control valves 225, 228, 23I and 234. An adjustable relief valve 244 is provided in the pipe line 243 which facilitates maintaining a constant operating pressure within the system by allowing any excess fluid under pressure to escape through a pipe 245 into the reservoir 240.

The operation of this machine will be readily apparent from the foregoing disclosure. When it is desired to start a grinding cycle, a manually operable switch 250 is closed to energize the solenoid SI which shifts the pilot valve 232 so that fluid under pressure shifts the valve member 233 toward the right thereby passing fluid under pressure from the pipe 243 through the pipe I99'to withdraw the index plunger I95 from engagement with the index plate I90. As the index plunger I95 moves to an inoperative position, it depresses the actuating plunger 290 of the limit switch LS2 to close the switch and thereby to energize the solenoid S2 which serves to shift the valve member 221 toward the right (Fig. 10) so that fluid under pressure passes through the pipe I55 to start the motor I15 and thereby to start an indexing movement of the turret wheel 15 to present the next workpiece into a grinding position.

The solenoid S4 is deenergized so that when fluid under pressure passes through the pipe I to start the index motor I15, fluid exhausts therefrom through the pipe I85, through control valve 228 and passes out through a slow speed throttle valve 249 and through the exhaust pipe 253 into the reservoir 245. The indexing movement of the turret starts slowly at a rate governed by the throttle valve 249.

As soon as the indexing movement of the turret starts, the cam 2 II on the plate 2") rides off the actuating roller 2I5 of the limit switch LSI thereby allowing the limit switch LSI to close. The closing of the limit switch LSI serves to energize the solenoid S4 to shift the pilot valve 229 and thereby to shift the valve member 239 toward the right (Fig. 10) so that fluid exhausting from the motor I15 through the pipe I85 may exhaust from the control valve 228 through a pipe 25! and through a throttle valve 252 and through an exhaust pipe 253 into the reservoir 245. The throttle valve 252 serves to control the speed of the motor I15 so as to control the speed of the indexing movement of the turret wheel 19.

The rotary indexing movement of the turret 15 continues at a relatively rapid rate as governed by throttle valve 252 until the turret 19 approaches an indexed position. As the turret 19 approaches an indexed position, the cam 2! on the plate 2I9 engages the actuating roller 215 and opens the limit switch LSI which breaks a circuit to deenergize the solenoid S4 thereby causing the control valve 228 to shift into the position illustrated in Fig. 10, so that fluid exhausting from the motor I15 through the control valve 228 passes through the slow speed throttle valve 249 so as to slow down the turret 10 before the index pawl I95 moves into engagement with the next notch I92 in the index plate I90. By manipulation of the throttle Valves 249 and 252, the slow and fast movement of the turret may be independently adjusted as desired.

The rotary indexing movement of the turret wheel 15 continues until the index plate I59 rotates through approximately and the index pawl I is moved into engagement with the notch I92 by the released compression of the spring I95. Movement of the pawl I95 into operative engagement with the notch I92 serves to open the limit switch LS2 thereby deenergizing the solenoid S2 which shifts the valve member 221 toward the left into the position illustrated in Fig. 10 to stop the flow of fluid under pressure to the motor I15.

When the plunger I95 moves upwardly into operative engagement with the notch I92, the limit switch LS3 is momentarily closed in a manner above described which serves to start a time relay 254 in motion. This time relay may be of any standard variety such as for example a Microflex time relay such as manufactured by the Signal Electric Corporation of Moline, Illinois. The time relay serves to control the duration of the grinding cycle. Setting in motion eased-t 11 of the time. relay Z54 serves to energize the solenoid S3 to shift the pilot valve 235 so as to cause the valve member 236 to shift toward the right (Fig. 10) so that fluid under pressure in the pipe line 243 may pass through the pipe I69, throughthe pipe I35 to move the slide H8 upwardly thereby engaging the work driving spindle in a manner above described. At the same time fluid under pressure in the pipe It?! passes through the pipe I49 to move the piston Idl and the rackbar I44 toward the left to impart a rotary motion to the work spindle and the workpiece 84 to rotate the workpiece through approximately 90 from position 84a into position 8 41) to grind partial cylindrical surfaces II and I 52 on opposed edges of the workpiece. At this time fluid under pressure in the pipe I69 builds up pressure within the pipe I13 to open the sequence valve I'I2 o that fluid under pressure within the pipe I69 may pass into the cylinder I55 to cause a transverse movement of the slide! to shift the workpiece 84 longitudinally so that the grinding wheels I8 and 38 will grind the remainder of the opposed sides of theworkpiece and also will engage and grind shouldered surfaces 84aand 8412, as shown in Fig. 13. As above described the sequence valve is arranged to delay the action of the piston I56 until the pistons I 3I and MI have completed their movements. The grinding operation continues with the wheels in engagement with the shoulders 84a and 84b untilthe time delay relay 254 operates aftera predetfirmined cycle to deenergiae thesolenoid S3. Deenergizing the solenoid S3 shifts the pilot valve 235 into the position illustrated in Fig. 10 so that the valve member 236 moves toward the left into the position illustrated. in which position fluid under pressure is admitted through the pipe I66 to cause a return movemento'f the-piston I il which serves to swing the workpiece from position 84b into position 84a to complete the grinding of the arcuate surfaces on the edge portion of the workpiece 84 adjacent to the shoulder faces 84a and 84b thereon. ,After the, workpiece has swung from position 84b into position 84a, the slide H8 is moved rearwardlytodisengage the driving spindle from the work spindlethereby to stop rotation of the work at which time. fluid under pressure passing through the, pipe I66 entering the cylinder I 55 causes a transversely movable slide 14 to move to an inoperative position ready for the next indexing operation. 'As above explained workpieces are. loaded into the machine in the work holder at the top of theturret wheel III (Fig. 3 On the next indexing movement of the turret Hi the workpiece moves into ;a grinding position.

. After a second indexing movement the workpiece 84 which has been ground will be indexed through 180 into position so that it 'may be removed from the work supporting arbor 92 by actuation of the ejecting plunger 2 I8. It will be readily apparent from the foregoing disclosure that once the cycle of operation is started by actuation of the manually operable switch 250 successive workpieces are automatically'ground to predetermined size, it being'merely necessary to manually load and eject workpieces in the work turret I0.

It will thus be seen that; there hasbeen provided by the invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be madeof the above invention and as many changes might be made in the 7 l2 embodiment above set forth, it is to be under stood thatall matter hereiiibefore set forth, or shown in the accompanying drawings is tobe interpreted as illustrative and not in a limiting sense.

I claim: I v

1. In a grinding machine having a spaced rotatable grinding wheels for-in fig a grinding throat having substantially parallel operative lines of grinding contact, a transversely movable slide movable in a direction parallel to the grinding throat, an indexible work turret thereon located between said wheels, a radially arranged rotatable work support on said turret, said support being arranged normally to support a work piece with its longitudinal axis aligned with the axis of rotation of the work support and its transverse axis in the plane of rotation of said turret, means intermittently to index said turret to move the work support to and from a grinding position and a Work support driving mechanism 'engag'eable to rotate said support relative to said turret through a partial rotation only when the support is in a grinding position so 'as to grind partial 'cylin'dr-ical surfaces on opposite edges of 'a work piece.

"2. In 'a grinding machine having a "pair "of spaced rotatable grinding wheels forming a grinding throat having substantially parallel operative lines of grinding contact,- a transversely movable slide movabl'e'ina direction parallel'to the grinding throat, an indexible "work turret thereon located between said wheels, -'a radially arranged rotatable work support'on said turret, said support being arranged n'ormailytto sup-port a work piece with its longitudinal-axis*aligned with the axis of the work support 'andits transverse 'axis in asubstantiallyvertical :pla'n'e, means intermittently to index 'said'turret 'to-mo've tlre work support to and from a grinding position, and a work support drivingm'eclranism arranged to engage and to rotate said support =relativ'e t'o said 'turret'through a partial rotation'to shiftthe transverse axis of the workpiece-from 'a vertical to a substantially horizontal plane only when the work support is in a grinding position soas to grind partial cylindrical surfaces on opp osite edges of "a work piece.

3. In a grinding riiachine'having a pai'r of spaced rotatable' grinding wheels; a transversely movable slide, an indexible work-turret ther'eon located between *said 'wh'e'els; aradially-arranged rotatablework support'on' said turret, "said work support being arrangedrnorinallyrto support a work piece with its longituclih'al-v'axisaligned with the axis of the work"suppo'rt and'fitstransverse axis in a substantiallyverticalfplane, Ih'eans'to indexsaid turret toholdtlre wdrksupport'to and from a grinding"position,=a work support' driving me chani'smto rotate said support relative-to said turret to shift the transverse axis of th'e work piece from "a 'vertic'alto a substantially horizontal position-sons to grind partiah cylindrical surfaces on opposite edges'of a workrpiece; andmeans to traverse said turret transversely "when the-work piece is in'ahoriaontal' position't'o cause a 'relative'ly transversing movement between the work piece and the-grmdingwheels -to-complete" the grinding operation on opposite edges of-the work piece. A

4. In a grinding machine having aspair -of spaced rotatable grinding wheels; a transverse- -1y movable indexible work-turret;between--said wheels, a radially arranged rotatable work-- support on said turret, said support being arranged I normally to support a work piece with its longitudinal axis aligned with the axis of the work support and its transverse axis in a substantially vertical plane, means to index said turret to move the work support to and from a grinding position, a work support driving mechanism to rotate said support so as to shift the transverse axis of the work piece from a vertical to a substantially horizontal position to grind partial cylindrical surfaces on opposite edges of the work piece, and means to traverse said turret transversely to cause a relative reciprocation between the work support and the grinding wheels to complete the grinding operation on opposed edges of a work piece, said driving mechanism serving thereafter to rotate said support in the opposite direction from a horizontal to a vertical position.

5. In a grinding machine, as claimed in claim 4, in which the axes of the grinding wheels are angularly arranged, a frusto-conical face on each of said wheels having substantially parallel elements at the plane of grinding contact for grinding opposite parallel edges on a work piece, and a second frusto-conical face on each of said wheels, the elements of said conical faces on each wheel beingat right angles to each other, said second frusto-conical faces serving to grind a shouldered portion on a work piece adjacent to said parallel edges.

6. In a grinding machine having a base, a pair of spaced rotatable grinding wheels forming a grinding throat having substantially parallel operative faces, a transversely movable slide, an indexible turret on said slide which is positioned midway between said wheels, a plurality of normally stationary radially arranged work spindles on said turret, said spindles being arranged normally to support a relatively fiat work piece with its longitudinal axis aligned with the axis of the spindle, a clutch between said spindle and the turret normally to hold the spindles against rotation with the transverse axis of the work piece in the plane of rotation of said turret, an indexing mechanism for said turret successively to position said spindles in a grinding position, and a spindle driving mechanism which is movable to an operative position when a work spindle is in a grinding position to disengage said clutch and thereafter to oscillate said spindle through a partial rotation so as to grind partially cylindrical parallel surfaces on opposite edges of the work piece.

7. In a grinding machine, as claimed in claim 6, in combination with the parts and features therein specified in which the transversely movable spindle rotating mechanism includes a rotatable driving spindle, means including a piston and cylinder to move said mechanism to and from an operative position, to engage the driving spindle with the work spindle, means including a piston and cylinder which is operative when a driving spindle is in an operative grinding position to rotate said driving and work spindles in one direction through a partial rotation so as to grind partially cylindrical parallel surfaces on the opposite edges of the work piece, and means to traverse said slide so as to traverse the work piece longitudinally relative to the grinding wheels to grind the remainder of the opposite edges thereon, said driving spindle rotating mechanism serving thereafter to rotate the work spindle in the opposite direction through approximately 90 so as to complete the grinding operation.

8. In a grinding machine, as claimed in claim 6,

in combination with the parts and features therein specified in which the spindle rotating mechanism includes a normally stationary rotatable driving spindle, a transversely movable slide to support said mechanism, means including a piston and cylinder to move said slide to and from an operative position, means including a piston and cylinder which is operative when a work spindle is in a grinding position to rotate said driving and work spindles in one direction through a partial rotation so as to grind partially cylindrical parallel surfaces on the opposed edges of a work piece, and means including a piston and cylinder to traverse said slide so as to traverse the work piece longitudinally relative to the grinding wheels to grind the remainder of the edges thereon, said spindle rotating piston and cylinder serving thereafter to rotate said spindle in the opposite direction through approximately so as to complete the grinding operation.

9. In a grinding machine having a base, a pair of spaced rotatable grinding wheels forming a grinding throat having substantially parallel operative faces, a transversely movable slide, a piston and cylinder to move said slide, an indexible turret on said slide which is positioned between said wheels, a plurality of normally stationary radially arranged Work spindles rotatably mounted on said turret, said spindles being arranged normally to support a work piece with its longitudinal axis in the plane of rotation of the turret, an indexing mechanism including a fluid motor for said turret successively to move said spindles to and from a grinding position, a normally inoperative spindle driving mechanism which is operative when a spindle is in a grinding position to engage and drive said spindle through approximately 90 so as to grind partially cylindrical parallel surfaces on the opposite edges of the work piece.

10. In a grinding machine having base, a pair of opposed spaced grinding wheels forming a grinding throat having substantially parallel operative faces, a transversely movable slide, and indexible turret on said slide which is positioned between said wheels, a piston and cylinder to move said slide, a plurality of normally stationary radially arranged work spindles rotatably mounted on said turret, said spindles being arranged normally to support a work piece with its longitudinal axis aligned with the axis of the spindle and its transverse axis in a substantially vertical plane, and indexing mechanism including a fluid motor for indexing the turret successively to move said spindles to and from a grinding position, a notched index plate, a spring pressed pawl successfully to locate said turret in predetermined index positions, a piston and cylinder to withdraw said pawl, a transversely movable slide on said first slide, a normally inoperative driving spindle thereon, a piston and cylinder to move said second slide to position the driving spindle in driving engagement with the work spindle when the latter is in an operative position, and a piston and cylinder to rotate the driving spindle through a partial rotation so as to swing the transverse axis of the work piece from a vertical to a horizontal position to grind partial cylindrical surfaces on opposite edges of a work piece.

11. In a grinding machine, as claimed in claim 10, in which a control valve serves to control the admission to an exhaust of fluid from the pawl cylinder to control withdrawal of said pawl to initiate a turret indexing movement, a second control valve to control the admission of fluid to the index motor, a third control valve to control the exhaust of fluid from the index motor, and a fourth control valve to control the admission to an exhaust of fluid from the work driver slide cylinder, the work driver rotating cylinder and the turret slide cylinder so as to control the grinding operation.

2. In a grinding machine, as claimed in claim 10, in which a solenoid-actuated control valve serves to control the admission to an exhaust of fluid from the pawl cylinder to control withdrawal of said pawl to initiate a turret indexing movement, a second solenoid-actuated control valve to control the admission of fluid to the index motor, a third solenoid-actuated control valve to control the exhaust of fluid from the index motor, a fourth solenoid-actuated control valve o control the admission to an exhaust of fluid from the work driver slide cylinder, the work driver rotating cylinder and the turret slide cylinder, an electric timer, a switch actuated loy and in timed relation with the indexing movement of said turret to start said timer, said timer serving after a predetermined time interval to deenergize said fourth solenoid-actuated control valve to terminate the grinding operation.

13. In a grinding machine, as claimed in claim 10, in which a solenoid-actuated control valve serves to control the admission to and exhaust of fluid from the pawl cylinder to control withdrawal of said pawl to initiate a turret indexing movement, a second solenoid-actuated control valve to control the admission of fluid to the in- 16 dex motor, a third solenoid-actuated control valve to control the exhaust of fluid from the index motor, a fourth solenoid-actuated control valve to control the admission and exhaust of fluid from the work driver slide cylinder, the work driver rotating cylinder and the turret slide cylinder, a switch actuated by movement of the pawl to an inoperative position to deenergize the first solenoid-actuated control valve to start the fluid motor and thereby initiate an indexing movement of the Work turret, an electric timer, a switch actuated by and in timed relation with the indexing movement of the turret to start said timer, said timer serving after a. predetermined time interval to deenergize said fourth solenoidactuated control valve to terminate grinding operation.

OIVA E. HILL.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,619,736 Kaufmann et a1 Mar. 1, 1927 1,635,339 Peets -1 July 12, 1927 1,797,857 Ford Mar. '24, 1931 1,891,657 Theler Dec. 20, 1932 FOREIGN PATENTS Number Country Date 222,913 Great Britain Oct. 8, 1924 

